Douglas Brent Hegdahl III (born September 3, 1946) is a former United States Navy petty officer second class (E-5) who was held as a prisoner of war during the Vietnam War. After an early release, he was able to provide the names and personal information of about 256 fellow POWs, as well as reveal the conditions of the prisoner-of-war camp.
Hegdahl was born on September 3, 1946, and graduated from Clark High School in Clark, South Dakota on May 24, 1966. On April 6, 1967, 20-year-old Hegdahl was knocked overboard by the blast from a 5-inch gun mount from the USS Canberra in the Gulf of Tonkin, three miles off the coast. He swam until he was picked up several hours later by Vietnamese fishermen who treated him well. Trying to cover for him, his shipmates did not report him missing for two days, so the commanding officer did not organize a search. Hegdahl was handed over to Vietnamese militiamen who clubbed him repeatedly with their rifles before moving him to the infamous "Hanoi Hilton" prison.
The interrogators first believed that Hegdahl was a commando or an agent. His story of being blown overboard seemed unbelievable to the interrogators. Hegdahl thought he would be much better off if he pretended to be of low intelligence. Hegdahl was physically maltreated for a few days before he was able to convince his captors that he was of little value for their propaganda campaign. His bumpkin demeanor and youthful appearance aided in his ability to convince them that he was no threat to them.
When asked to write statements against the United States, he agreed, but pretended to be unable to read or write, which was believable to his Vietnamese captors. Thinking they had someone who would be easily turned to their cause, they assigned someone to teach Hegdahl to read. After Hegdahl appeared to be incapable of learning to read and write, his captors gave up on him. Later, he came to be known to the Vietnamese as "The Incredibly Stupid One", and he was given nearly free run of the camp.